Stem cells have once again flitted through the news cycle, this time as a result of a new and growing industry that has arisen around the use of adult stem cells in cosmetic treatments that purport to both be more effective and less dangerous than traditional procedures such as the infamous and potentially toxic Botox injections.

But the scientific basis for the use of stem cells for cosmetic procedures is entirely tentative. To date, the US Food and Drug Administration has not approved any stem cell-based products for use, aside from a small number of umbilical cord blood-derived treatments for blood cancer as well as hereditary metabolic and autoimmune disorders.

Cosmetic treatments of any variety are subject to far less scrutiny than medical treatments, however, and this is what is currently allowing an increasing amount of doctors throughout the country to charge as much as $30,000 for procedures whose value are more or less unproven from the standpoint of official studies, clinical trials, and peer reviews.

Considering that so few medical products involving stem cells have been approved, a high degree of skepticism should probably be applied to any magical claims about the potential for stem cells to make one look younger, or to otherwise repair one’s perceived cosmetic iniquities. A terrifying article that appeared last December in The Scientific American suffices to support this contention.

But stem cells, whether of the adult of cord-blood variety, are believed to have regenerative properties that could repair all manner of human diseases and conditions, from cardiovascular conditions, to autoimmune diseases. The following five companies are biotechs that are working to ostensibly better the human condition through the use of stem-cell technology, and are all in the midst of clinical trials for various treatments, or on their way to beginning them

Osiris Therapeutics (OSIR) — With a market cap of $377 million, the Columbia, Maryland-based Osiris Therapeutics focuses on the development and marketing of stem cell products to treat serious inflammatory, autoimmune, orthopedic, and cardiovascular conditions. The company’s shares are currently priced at $11.45 and are up over 38 percent over the last six months.

Pluristem (PSTI) — The Israel-based Pluristem develops stem cell therapies from placenta cells for a number of diseases, and is currently preparing for clinical trials for a Peripheral Artery Disease treatment. The company has a market cap of $173.9 million, with shares trading at $2.98, down 7 percent over the past half year.

Cytori Therapeutics (CYTX) — Cytoris Therapeutics uses adult stem cells to develop regenerative therapies for cardiovascular conditions and soft tissue defects. The US company has a market cap of $188.9 million with shares currently priced at $2.82, up 2.5 percent over the last six months.

Neostem (NBS) — The New York, NY-based Neostem owns and operates a number of subsidiaries in the stem-cell based regenerative medicine industry that develop treatments for cardiovascular, autoimmune, and inflammatory conditions. The company is nearing clinical trials for a periodontitis treatment. With a market cap of $117.7 million, shares are currently priced at $7.05, up 10 percent over the past six months, and 17 percent year-to-date.

Advanced Cell Technology ($ACTC) — The Santa Monica, CA-based Advanced Cell Technology uses both adult and embryonic stem cells to develop treatments for retinal, blood, and heart diseases, and has recently initiated two different clinical trials for degenerative retinal disease. With a market cap of $179 million, shares are currently priced at $0.07, down $0.01 over the past six months.